Slack-adjuster for brakes.



u... mw 5, d -w Z BHBETS-SHEET lY C. L. BUNDY.

SLAGK ADJUSTER FOR BRAKES.

APPLICATION ILED JUNE 4,1910. 988,970. Patented Apr.11,1911.

. MZK/.0 5565,'

2 SHEETS-SHEET 2.

Z/Yoczyzff Patented Apr. 11, 1911.

@fm L. bm

C. L. BUNDY.

SLAGK ADJUSTER POR BRAKES.

UNITED STATES PATENT OFFICE.

GYRUS L. BUNDY, 0F KINGSLANI), NEW JERSEY, ASSIGNOR OF FIFTY-ONE PERCENT.

IO WALTER P. MURPHY, OF CHICAGG, ILLINOIS, AND TWENTY-FOUR AND FIVE-TENTI-IS PER CENT. T0 JULIUS J. .ACKER, 0F I-IORTON, KANSAS.

SLACK-ADJUSTER FOR BRAKES.

Specification of Letters Patent.

Patented Apr. 11, 1911.

Application filed June 4, 1910. Serial No. 564,942.

To all whom it 'may concern:

Be it known that I, Crans L. BUNDY, a citizen of the United States, anda resident of Kingsland, Bergen county, New Jersey, have inventedcertain new and useful Improvements in Slack-Adjusters for Brakes, ofwhich the following` is a specilication.

My invention relates to slack adjuster-s for brakes and is particularlydesigned to automatically compensate for the wear on brake shoes as usedin the ordinary and well known air brake systems.

I am aware it is well known to use means for compensating for the wearon brake shoes, this ordinarily being accomplished by some suitabletake-up device used in connection with the live lever rods. These rodsordinarily are allowed a certain predetermined amount of movement ingoing from their application to their release positions, and the take-upmechanism is designed to operate in connection with the further movementof the live lever rods as wear increases on the brake shoes.

In my improved device, the push rod used in connection with the brakecylinder, has a certain predetermined amount of lost motion before itmoves the various parts associated with the cylinder lever and the livelever rod, means being provided for moving the slack adjuster withrelation to the cylinder lever as wear on the brake shoes progresses.The means for accomplishing this result consists in a casing or housingwithin which are inclosed a plurality of adjusting blocks. This housingalways retains the same relative position with relation to the push rod,but as wear progresses one or more of the blocks, just mentioned, dropbehind the cylinder lever, which is thus always kept in the properposition to apply the brakes regardless of the amount of wear which hastaken place on the brake shoes. It will be apparent that by thisconstruction greater simplicity is attained with a consequent less costof original installation and up-keep. These and other advantages of myinvent-ion will be more readily understood by reference to theaccompanying drawings in which:

Figure 1 is a plan view showing my improved slack adjuster in connectionwith the brake cylinder, cylinder lever and its associated parts. Fig. 2is a side elevation of the parts shown in F ig. 1. Fig. 3 is an enlargedvertical section through my slack adjuster and the parts directlyassociated therewith, the adjusting blocks being shown in their normaloperative positions. Fig. 4t is a vertical section similar to Fig. 3,showing the adjusting blocks as elevated in order to allow full releaseof the cylinder lever and its associated live lever rods. Fig. 5 is atransverse section on the line 5 5 of Fig. 3. Fig. 6 is a transversesection on the line 6 6 of Fig. 3. Fig. 7 is a transverse section on theline 7-7 of Fig. 4C.

The push rod 10 operates in connection with the brake cylinder 11 in theordinary and well known manner.

The slack adjuster 12 is provided with a sleeve 13 having the slot 14within which the pin 15, passing through the end of the push rod 10,operates. The slack adjuster 12 has near its bottom, the opening 16through which the cylinder lever 17 is adapted to move. This cylinderlever 17 is pivotally connected at one end with the hand brake rod 18and on its opposite end with the live lever rod 19 which is connected inthe well known manner with the brake shoes at one end of the car. Thehedge rod 20 is ivotally connected to the cylinder lever 1 at a pointmidway between its connection with the live lever rod 19 and itsconnection with the slack adjuster, as will be described hereafter. Onits opposite end, the hodge rod 2() is pivotally connected with thelever 21, which in turn is pivotally connected at one end with the boss22 on the brake cylinder 11 and at its opposite. end with the live leverrod 23.

The cylinder lever 17 operates on the brackets 24 which are attached tothe bottom of the car by means of the bolts 25. In this way the cylinderlever 17 is always held in a horizontal position. The two rods or bars26, 2G are held in engagement with the top surface of the cylinder lever17 by means of the springs 27 the tension of which is adjusted by meansof the nuts 28 on the bolts 25. It will be evident that by adjusting thenuts 28, the frictional engagement with the upper surface of thecylinder lever 17 may be correspondingly adjusted.

The slack adjuster is provided with a cover 29 which has holesregistering with pins 30 through which pass the Cotter pins 31, thusholding the cover securely in position. When the cover 29 is removed,the adjusting blocks 32 may be placed inside of the slack adjuster'.Connected with the cylinder lever 17 by means of the pivot 33, is therod 34 which passes forwardly through a suitable opening in the end ofthe slack adjuster. It will be apparent that when the cylinder lever 17is moved to the position shown in Fig. 4, all of the adjusting blocks 32Will be held in an elevated position on top of the rod 34. Each of theadjusting blocks 32 has a vei'tical slot 35 Within which the rod 3G isadapted to opera-te. This rod has on its end a pin 37 which engages theslot 38 in the end of the crank 39 which is mounted on the release rod40. The end of rod 36, opposite to that having the pin 37, is beveledand adapted to slide over the inclined surface 41 Within the casing ofthe slack adjuster. The opposite end of the slack adjuster has the slot42 which serves to guide the rod 36 by means of its pin 37. The slot 42is parallel With the surface 41 so that it will be evident that if therelease rod 40 is rotated, the rod 36 will be elevated and moved to theleft into the position shown in Fig. 4, thereby elevating at the sametime all of the adjusting blocks 32.

As best shown in Fig. 1, the portion of the cylinder lever 17 Within theslack adjuster 12 has a slightly curved edge 43 forming engagement withany one of the adjusting blocks 32 which may have dropped into aposition behind the cylinder lever 17, as Will presently be explained.

Having thus described the construction of the parts of my improved slackadjuster, its operation may novv be readily understood. Then the brakesare in their normal release position, the pin 15 on the end of the pushrod 10, Will lie at the left hand end of the slot 14. If it is desiredto apply the brakes, the push rod 10 is moved to the right in the Wellknown manner, and all ofthe parts remain stationary until the pin 15reaches the right hand end of the slot 14. Then this happens pressure isapplied to the cylinder lever 17 through the slack adjuster Which itselfis carried to the right. The cylinder lever turns on its connection withthe hedge rod 20 as a pivot and the live lever rod 19 is moved to theleft, thereby applying the brakes. At the same time, the hedge rod 20 iscarried to the right, thereby serving to move the lever 21 and the livelever rod 23 to the right thereby applying the brakes simultaneously onboth ends of the car. We Will assume that in a single application of thebrakes, the brake shoes have become Worn to a considerable extent. Thenit is desired to release the brakes, the push rod 10 is moved to theleft, thereby immediately releasing the pressure of the brake shoes onthe car Wheels and holding them lightly in contact therewith, orpossibly just clear of the Wheels. The push rod 10 continues to move tothe left until the pin 15 reaches the left hand end of the slot 14.Inasmuch as the slot 14 is of just sufficient length to give the desiredrelease of the brake slices, and since during this single applicationthe brake shoes have become worn to a considerable extent therebycausing the slack adjuster 12 to move an undue distance to the right, itwill be apparent that the left hand end of the slot 14 will be engagedbefore the push rod 10 has returned to its normal position; the slackadjuster 12 will in this Way be moved to the left as further movement ofthe push rod 10 continues, but by means of the friction rods 26, thecylinder lever 17 Will be prevented from moving vvith the slackadjuster. The result of this will be that as the slack adjuster 12continues to move to the left, one or more of the adjusting blocks 23ivill drop behind the cylinder lever 17 and We shall have the conditionindicated in Fig. 3. On the next application of the brakes, the push rod10 Will move to the right until the right hand end of the slot 14 isreached, when the brake slices will immediately be applied to the Wheelson the application of further pressure from the push rod through theslack adjuster. As further Wear occurs on the brake shoes additionaladjusting blocks 32 will drop behind the cylinder lever 17 therebymoving its pivotal point farther to the right. The function of the hodgerod 20 is, of course, as is vvell known, to regulate the pressure at thetivo ends of the car, so that it is immaterial on which end of the carthe Wear on the brake shoes occurs, as the slack adjuster vvill operateequally Whether the -vvear occurs on the brake shoesl associated Withthe live lever rod 19 or the live lever rod 23. Then it is desired toreplace a brake shoe and to obtain a full release of the live lever rods19 and 23, the rei lease rod 40 is rotated, thereby moving all of theadjusting blocks 32 into the position shown in Fig. 4 in Which case theslack adjuster 12 may be moved to its extreme position to the leftthereby moving the live lever rods 19 and 23 to their full releasepositions so that ready access is obtained to the brake shoes.

It will be apparent to those skilled in the art that many changes couldbe made in the l detailed construction of the parts which I havedescribed Without departing from the spirit of my invention.

that I claim is:

1. A slack adjuster comprising a casing and adjusting means Within saidcasing, said adjusting means adapted to actuate a cylinder lever Whenmoved in one direction and to form nevv engagement with said cylinderlever when moved in the opposite direction,

thereby leaving the cylinder lever in a stationary position,substantially as described.

2. In a brake system, the combination of a push rod, a cylinder lever,and a slack adjuster comprising a casing and adjusting means within saidcasing, said adjusting means adapted to actuate the cylinder lever' whenmoved in one direction and to form new engagement with the cylinderlever when moved in the opposite direction and allowing lost motion withrespect to said push rod, substantially as described.

3. A slack adjuster comprising a casing and a plurality of adjustingblocks within said casing, said slack adjuster adapted to engage acylinder lever when moved in one direction and to form new engagementtherewith by means of said blocks when moved in the opposite direction,substantially as described.

ll. In a brake system, a push rod, a cylinder lever, and a slackadjuster comprising a casing and a plurality of adjusting blocks, saidslack adjuster having lost motion with respect to said push rod andadapted to actuate said cylinder lever when moved in one direction andto form new engagement with the same when moved in the oppositedirection, substantially as described.

5. In a brake system, the combination of a push rod, a cylinder lever, aslack adjuster comprising a casing and a plurality of adj usting blockswithin said casing, said slack adjuster adapted to engage said cylinderlever when moved in one direction and to move independently of thecylinder lever but forming new engagement therewith by means of saidadjusting blocks when moved in the opposite direction, and means forreleasing said blocks from engagement with said cylinder lever, therebyallowing movement of the cylinder lever to full release position,substantially as described.

G. In a brake system, the combination of a cylinder lever, a slackadjuster comprising a casing and a plurality of adjusting blocks withinsaid casing, and means for preventing engagement of said blocks withsaid cylinder lever except on one side, said slack adjuster therebyadapted to actuate saidcylinder lever when moved in one direction and toform new engagement therewith when moved in the opposite direction,substantially as described.

7. In a brake system, the combination of a cylinder lever, a slackadjuster comprising a casing and a plurality of adjusting blocks withinsaid casing, and means for preventing engagement of said blocks withsaid cylinder lever except on one side, said slack adjuster therebyadapted to actuate said cylinder lever when moved in one direction andto form new engagement therewith when moved in the opposite direction,and means for releasing said blocks from engagement with said cylinderlever, substantially as described.

8. A slack adjuster comprising a casing, a plurality of adjusting blockswithin said casing, each of said blocks having a vertical slot therein,and releasing means adapted to raise said blocks thereby removing themfrom engagement with said cylinder lever, substantially as described.

9. A slack adjuster comprising a casing having an oblique surface on itsinterior, and a plurality of adjusting blocks within said casing andadapted to engage a cylinder lever, each of said blocks having avertical slot therein, a rod engaging said oblique surface and movablewithin said slots, and means for raising said rod thereby removing saidblocks from engagement with t-he cylinder lever, substantially asdescribed.

10. A slack adjuster comprising a casing having an oblique surface onits interior and a slot in said casing parallel with said obliquesurface, a plurality of adjusting blocks within said casing and adapt--ed to engage said cylinder lever, each of said blocks having a verticalslot therein, a rod adapted to engage said oblique surface and a. slotin said casing and passing through the slots in said adjusting blocks,and means for raising said rod thereby causing disengagement of saidadjusting blocks from said cylinder lever, substantially as described.

CYRUS L. BUNDY.

Witnesses RUDOLPH C. E. MAY, JOHN PRITGHARD.

Copies of this patent may be obtained for five cents each, by addressingthe "Commissioner of Patents, Washington, D. G.

